Starter drive for internal combustion engines



4 Nov. s, 1938. Y E LA 2,135,653

' STARTER DRIVE FOR INTERNAL COMBUSTION ENGINES Filed July 31, 1935' 3 Sheets-Sheet l NOV. 8, 1938. SEKELLA STARTER DRIVE FOR INTERNAL COMBUSTION ENGINES Filed Ju 3 Sheets-Sheet 2 INVENTOR.

ATTORNEY.

Nov. 8, 1938. Y. SEKELLA 2,135,653

STARTER DRIVE FOR INTERNAL COMBUSTION ENGINES Filed July 31, 1955 3 Sheets-Sheet 3 1N VENTORv wme BY W ATTORNEY.

Patented Nov. 8, 1938 STARTER DRIVE FOR INTERNAL COMBUS- I TION ENGINES Youston Sekclla, Elmira, N. Y., asslgnor to Eclipse Machine Company, Elmira, N. Y.,a corporation I of New York iApp'lication July31, 1935, Serial No. 34,044

'9 Claims.

I started.

It is an object of the present invention to pro- I vide a novel starter drive which is simple and economical in construction, small in size and powerful and eilicient in operation. A

It is another object to provide such a device which includes anovel form of yielding driving connection. g

It is a-further object to provide such a device which embodies a yielding driving connection including a compression spring in which the spring serves as a keying means for the transmission of torque.

It is another object to provide such a device embodying, novel provisions for preventing re- 20 bounding of the starting pinion when it is automatically demeshed.

It is another object to provide such a device in which separate compression springs are provided to enforce meshof the pinion and to form the yielding driving connection. I

.It is a further object to provide such a device in which. the compression spring for enforcing mesh also serves to transmit initial torque.

Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawings in which:

Fig. 1 is a side elevation partlydn section of one preferred embodiment of the invention, the device being shown in disengaged position;

Fig. 2 is a sectional view thereof taken substantially on the line 2-4 of Fig.1;

Fig. 3 is'a side elevation of the same rotated through an angle of 90 degrees;

Fig. 4 is a view similar to Fig. 1 showing the device in cranking position;

I Fig. 5 is a detail in perspective of adriving disc; Fig. 61s a detail in perspective of the compres- 4 sion and torque transmitting spring;

modified formlof compression and drive spring;

Fig. 7 is a detail'insldeelevation showing a Fig. 8 is a side elevation partly in section of a r second embodiment of the invention;

Fig. 9 isa view similar to'Fig. 8 showing the parts in cranking position; I

Fig.'10 is a side elevationthereof partly broken away showing the parts in the positions assumed inf'caseof tooth abutment between the pinion 55' and engine gear;

(Cl. Hr-7) Fig. 11 is a section taken substantially on the linell-Il of Fig. 8; v

Fig. 12 is a section taken substantially on the line l2-l2 Of Fig. 8;.

Fig. 13 is a detail in perspective of a driven 5 disc and clutch member with the housing and anchoring member for the mesh-enforcing spring, the parts being separated for the sake of clarity;

Fig. 14 is a side elevation partly in section of a further embodiment'of the invention, the parts 10 being shown in idle position;

Fig-15 is a similar view showing the parts incranking position; and

Fig. 16 is a similar view showing the parts in the positions assumed in case of tooth abutment 16 between the pinion and engine gear.

Referring first to Fig. 1 of the drawings, there is illustrated a starter drive including a power shaft I which may be the extended armature shaft of a starting motor not shown. A hollow sleeve 2 20 is fixed on the power shaft in any suitable manner as by means of a key 3 and set screw 4 and carries freely journalied thereon an actuating member in the form of a screw shaft 5. Longitudinal movement of the screw shaft 5 to the left is limited by a shoulder 6 on the sleeve 2, and movement thereof to the right is limited by an abutment in the form of a stop nut 1 threaded on the end of said sleeve.

An engine driving member in the form of a pinion 8 is freely journalled on the power shaft l in position to be moved into and out of engagement with a member such as a flywheel gear 8 of the engine to be started. A nut I l is threaded on the screw shaft 5 and is splined to the pinion 8 for rotation in unison therewith by means of a barrel I! having slots l3 formed to receive radially extending lugs H on said nut. The nut is retained in the barrel by suitable means such as a split ring l5, and the nut and pinion are normally maintained in extended relation by means of a compression spring It. The nut II is normally maintained against the heel ID of the thread of screw shaft 5 by means of alight compression spring l'l bearing on the stop nut 1, thereby maintaining the pinion 8 in idle position.

A yielding driving connection between the screw shaft Sand the sleeve 2 is provided in the form of a heavy compression spring I8 formed from radially flattened stock, the end convolutions of which are tapered and provided with fiat driving abutments l9, 2| (Fig. 6). Driving and driven discs 22 and 23 respectively are provided which conform to the terminal convolutions of the spring l8 and are provided with shoulders 24 and 25 respectively adapted to engage the abutments I9 and 2| on the spring I8. The driving disc 22 is non-rotatably connected to the sleeve 2 as by a double D section indicated at 26 and the driven disc 23 is similarly connected to the screw shaft 5 as indicated at 2'! (Fig. 2). spring I8 serves in efiect as a spline to connect the screw shaft to the drive shaft I. Referring more particularly to Figs. 3 and 4,. it will be seen that the groove 28 in the spring I8 which defines the driving abutment 2i is wider than the shoulder 25 of the driven disc 23 so as to provide substantial rotary lost motion between the spring and disc. The longitudinal position of the disc 23 is defined by the shoulder 30 at the end of the threaded portion of the screw shaft, and the parts are preferably so dimensioned that the spring I8 is assembled under initial compression whereby the screw shaft is urged against the abutment I, and friction between the parts is sufficient to suitably damp such lost motion.

In the operation of this embodiment of the invention, rotation of the power shaft I r is transmitted through the sleeve 2 and double D section 26 to the driving disc 22. Shoulder 24 on disc 22 thereupon engages the driving abutment IS on spring I8, causing torque to be transmitted through the spring to the driven disc 23 by engagement of the abutment 2I against the shoulder 25. Rotation ,of the driven disc 23 is'transmitted through the doubleD section 21 to the screw shaft 5 whereby the nut II is traversed along the screw shaft, causing the. pinion 8 to mesh with the engine gear 9. When the nut II *pinion 8 and cause the engine to be cranked.

When the engine starts, the overrunning of the pinion 8 causes the nut II to be rapidly'returned to its idle position against the heel III of the thread on the screw shaft, rebounding of the nut being prevented by the damped lost motion of shoulder 25 of. driven disc 23 in groove 28 of spring I8.

Should the teeth of the pinion 8 abut against the teeth of the engine gear 9 during the meshing operation, the spring I6 in barrel I2 yields and permits the nut II to move forward until suflicient friction is built up in the threadsto cause the pinion to be indexed into proper registry, whereupon the spring I6 expands and snaps the pinion into mesh.

The embodiment of the invention illustrated in Figs. 8 to 13 inclusive comprises a power shaft 3I on which is fixed a hollow sleeve 32 by suitable means as indicated at 33. A screw shaft 34 is freely journalled on the sleeve 32, being retained thereon by a stop nut 35 threaded on the end of said sleeve. A pinion 36 is freely journalled on the power shaft 3| in position to be moved into and out of engagement with a member such as a flywheel gear 31 of the engine to be started and is rigidly connected by means of a barrel 38with a nut 39 threaded on the screw shaft 34.

A driving disc 4| is non-rotatably mounted on the end of sleeve .32 as by meansof a double D section indicated at 42 in Fig. 11 and is arranged to receive the terminal convolution of a heavy compression spring 43' and drive the same by means of shoulders 44 (Fig. 9) on the disc. en-

16 will thus be seen that the gaging abutment surfaces 45 of the spring. A driven disc and clutch member 46 is provided with shoulders 41 (Fig. 13) adapted to be engaged by abutment surfaces 48 (Fig. 9) of the spring and is mounted on a housing member 49 loosely mounted on shaft 32 and provided with openings 5I (Fig. 13) adapted to receive extensions 52 of the shoulders 41 of discs 46 in order to key the parts together. A comparatively light torsion and compression spring 53 is mounted on sleeve 32 and is provided with anoutturned end 54 adapted to be received in an opening 56 in the housing 49. The opposite end of spring 53 is adapted to enter an opening 51 (Fig. 8) in a clutch member 58 suitably fixed on the end of the screw shaft 34, the spring 53 being assembled undersufilcient initial compression to yieldingly maintain the screw shaft in its normal position against the stop nut 35. g

In the operation of this embodiment of the invention, initial rotation of the power shaft 3| is transmitted through sleeve 32, driving disc 4i,

spring 43, and driven disc 46 to the housing mem ber 49. Rotation of this housing member is yieldably transmitted by spring 53 to screw shaft 34 which causes the nut 39 to be traversed along clutch member 56 engages clutch member'46,

whereupon further torque and pressure are transmitted through said clutch members, thus limiting the flexure of the light spring 53. Spring 43 is then compressed and torqued until the pressure and friction built up in the threads of the screw shaft, nut 39 and stop nut 35 becomes sufficient to cooperate with the spring 43 to cause rotation of the pinion 36. When the engine starts, the overrunning of pinion 36 permitsthe parts to return to their idle positions.

Should the teeth of the pinion 36 abut the teeth of the engine gear '31 during the meshing operation as illustrated in Fig. 10, the light compression spring 53 is compressed until sufficient torque is built up in the threads to index the pinion. When the pinion is thus indexed, the spring 53 expands and snaps it into mesh,

whereupon mesh is completed and cranking takes place as usual.

The embodiment of the invention illustrated in Figs. 14, 15 and 16 comprises a power shaft 6| on which is rigidly mounted a sleeve 62 by suitable means as indicated at 63. ,A screw shaft V 64 is loosely journalled on the sleeve, 62, being retained thereon by a stop nut 65 threaded on the sleeve and being normally held in engagement with the stop nut by a light compression spring 66. I

A nut 61 is threaded on the screw shaft and rigidly connected by abarrel 68 to a pinion 63 which is freely journalled on the power shaft H and movable therealong into and out of engagement with a member of the engine to be started" such as the flywheel gearII. The pinion is nor mally maintained in idle position by means of an antidrift spring 10 mounted on the stop nut 65 I and cooperatingwith the nut 61.

A yielding driving connection between the sleeve 62 and screw shaft 64 is provided com-' prising a heavy compression spring 12 having sleeve and. screw shaft respectively.- The discs 15 are shaped to conform to the end convolutions of spring 12 and are provided with shoulders 16 adaptedto cooperate with abutments I3 wherebyrotation of disc 14 in the-direction of the arrow on shaft 6| is transmitted directly to the spring 12, and from said spring to disc l5,while disc 15 may overrun the spring and the spring may overrun the disc I2. Expansion of spring 12 is preferablylimited by a suitable housing 11 enclosing'the spring and discs 14 and T5.

In the operation of this embodiment of the invention, rotation of power shaft 6| is transmitted through sleeve 62, driving disc 14, spring 12, and driven disc 15 to the screw shaft 64 which causes traversal of nut 61 into engagement with stop nut 65, thus placing pinion 69 in mesh with engine gear ll. Further rotation of the power shaft causes screw shaft 64 to be'forced back,

first compressing the light spring 66 until the shoulder 18 at the end of the threaded portion of the screw shaft engages'the driven disc 15, whereupon further traversal of the screw shaft is resisted by the compression of the heavy spring 12. When the friction between the threads of the screw shaft and nut has thus been built up sufficiently, the pinion 69 is rotated to crank the engine. When the engine starts, the overrunning of pinion 69 permits the parts to return to idle position, rebounding of the pinion and connected parts toward meshing position being prevented by the overrun'ning connection 13, I6 between the discs 14 and I and spring 12 which permits the screw shaft 64 with its. associated parts to continue to rotate until their momentum is dissipated.

In case of tooth abutment between the pinion and engine gear as illustrated in Fig. '16, the light compression spring 66 yields to permit indexing of the pinion whereupon it expands and snaps the pinion into initial mesh, whereupon meshing and cranking take place as usual.

vided splined respectivelyto the sleeve 81 and screw shaft 88, shaped 'to'i conform to the end convolutions of thefs'pi'ing and .provided with soulders 89 and 9| adapted to cooperate with the abutments 83 and 84 nespectively.

Although certain embodiments of the invention have been shown and described in detail, it will be understood that other embodiments are possible and that various changes may be made in the construction and arrangements of the parts without departing from the spirit of the invention as defined in the claims appended hereto.

What is claimed is:

1. An engine starter drive including a drive shaft, a screw shaft freely journalled thereon, a fixed abutment and a yielding abutment on the drive shaft locating the screw shaft thereon, a nut threaded on the screw shaft and confined thereon by said abutments, an engine driving member,

and means for actuating the same from said nut, said yielding abutment including 'means for providing a lost motion rotary connection between the drive shaft and screw shaft, and being assembled under pressure for frictionally damping said lost motion.

2. In an engine starter drive, a drive shaft, a screw shaft rotatably and slidably mounted thereon, a nut threaded on the screw shaft, an engine driving member on the drive shaft, means connecting the nut and engine driving member for rotation and longitudinal movement in unison, a'fixed abutment on said drive shaft for the screwshaft and said nut, a light spring and a heavy spring for opposing longitudinal movement of the screw shaft away from its abutment, and means for connecting the heavy spring directly to the screw shaft after a predetermined compression of the light spring.

3. In an engine starter drive, a drive shaft, a screw shaft rotatably and slidably mounted thereon, a nut threaded on the screw shaft, an engine driving member on the drive shaft, means connecting the nut and engine driving member for rotation and longitudinal movement in unison, a fixed abutment on said drive shaft defining the normal position of the screw shaft and the operative position of said nut, a light compression spring and a heavy compression spring in series urging the screw shaft against its abutment and transmitting rotation thereto from the drive shaft, and means for clutching the heavy spring directly to the screw shaft after a predetermined compression of the light spring.

4. In an engine-starter drive, a compression spring formed of flattened wire having square ends, a longitudinally fixed driving disc and a longitudinally movable driven disc having shoulders adapted to cooperate with said square ends for transmission of torque, a screw shaft splined to the driven disc, a pinion adapted to engage and drive a member of an engine to be started, a nut threaded on the screw shaft, connecting means to' actuate the pinion from said'nut, means for limiting traversal of the nut and screw shaft away from the driving spring, means for limiting traversal of the screw shaft toward the spring, and yielding means urging the screw shaft away from the spring.

5'. An engine starter drive including a drive shaft, a screw shaft freely journalled thereon, a fixed abutment and abutment means on the drive shaft including a compression and torsion spring locating the screw shaft thereon, a nut threaded on the screw shaft and confined thereon by said abutments, an engine driving member, means for actuating the same from said nut, and means operative after a, predetermined longitudinal movement of the screw shaft for coupling said spring to transmit rotation from the drive shaft to the screw shaft.

6. In an engine starter drive, a drive shaft, a member freely journalled thereon adapted to engage and drive a member of the engine to be started, an actuating member rotatably and slidably mounted on the drive shaft and having connections with said engine driving memberwhereby relative rotation causes relative translation thereof, yielding means for opposing longitudinal movement of the actuating member away from the engine member and for torsionally transmitting rotation from the drive shaft to said actuating member, and a stop for limiting longi' tudinal movement of the actuating member and engine driving member toward the engine mem-- 7. In an engine starter drive, a compression spring formed of flattened wire having terminal abutments, a longitudinally-fixed driving disc and a longitudinally movable driven disc: arranged to'conform with and compressively support the end convolutions of the spring, and having shoulders adapte to cooperate with said abutments for transmission of torque; a screw shaft slidably splined to the driven disc, a pinion adapted to engage and drive amember of an,

10 engine to be started, a nut threaded on the screw shaft, connecting means to actuate the pinion from said nut, and means forlimiting traversal of the nut away from the driving disc, so arranged that transmission of cranking torque causes the movable discto: approach the fixed disc and compress the spring therebetween.

8. In an engine starter drive, a drive shaft, 9. member freely journalled thereon adapted to em gage and drive a member of the engine to be started, an actuating member rotatably and slidably mounted on the drive shaft and having con nections with said driving member whereby relative rotation causes relative translation thereof,

yielding means for lightly cushioning the application of translatory force from the actuating member to the driving member, yielding means for strongly resisting longitudinal movement of the actuating member away from said engine member, said latter yielding means being arranged to transmit'rotation from the driving shaft to the actuating member, a stop for limiting longitudinal movement of the actuating member toward the engine member, and means. for limiting the flexu re of said first-mentioned yielding means due to obstruction of the'translation of the driving member. I

9. An engine starter drive including a drive shaft, a screw shaft freely journalled thereon,

a fixed abutment and a yielding abutmenton the drive shaft locating the screw shaft thereon,

a nut on the screw shaft confined thereon by said abutments, an engine driving member, and means for actuating the same from said nut, said yielding'abutment including means providing a torsional'driving connection between the drive shaft and screw shaft capable of initial slippage, said connection being assembled under pressure to frictionally'resist such slippage.

YOUSTON SEKELLA. 25 

